Research, design, implementation of mixing and releasing structure in spring rolls making machine

MINISTRY OF EDUCATION AND TRAININGHO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION GRADUATION THESIS MAJOR: MACHINE MANUFACTURING TECHNOLOGY INSTRUCTOR: DUONG THI VAN ANH PHAM LE

INTRODUCTION

Rationale

Despite notable progress in our country's mechanical engineering industry, there is still a significant disparity compared to developed nations, particularly in precision mechanics and specialized machinery for sectors like healthcare, construction, and production lines To close this technological gap, the mechanical engineering sector must not only focus on targeted research investments but also prioritize the swift adoption of advanced technologies, which will help save time and reduce costs associated with research and machinery.

The growth of the automation industry in our country is evident through the establishment of automated production lines and manufacturing facilities However, reliance on imported technology and high costs have hindered widespread adoption, limiting the expected economic benefits To address this, there is an urgent need for domestic research and production of Vietnamese-branded automated machinery, a challenge that is gaining significant attention in research initiatives.

The food processing industry is crucial for both domestic and global economies, driving long-term economic efficiency and significantly influencing other sectors The growing demand for processed food products has bolstered the industry's strength, with established enterprises playing a vital role in economic production.

After receiving a proposal from Mr Le Thanh Huy, the director of CODIA Industrial

Driven by our commitment to enhance production processes in machine manufacturing technology, we meticulously analyzed earlier versions to pinpoint areas for improvement Consequently, our team initiated a project focused on the "Research, Design, and Implementation of a Mixing and Releasing Structure in Spring Roll Making Machines."

We hope that this project will help Ms Nhung Dang and Thanh Linh Restaurant in

Illinois, USA, to thrive, while also contributing to the advancement of specialized machinery production, particularly in the automation industry and the field of mechanical engineering

Figure 1.2: Diners are having a meal at Thanh Linh Restaurant

Scientific and practical significance of the project

- Improving production processes: Research and development of the spring roll wrapping machine can contribute to enhancing production processes, increasing productivity, and production efficiency

- Enhancing product quality: The spring roll wrapping machine, developed through scientific research, can help improve the quality of spring rolls, ensuring uniformity and reliability in the production process

- Reducing labor intensity: The machine helps reduce manual labor and allows workers to perform tasks over longer periods

- Increasing labor productivity: It addresses bottlenecks during work, enabling workers to handle tasks that are not automated

- Boosting Thanh Linh Restaurant's productivity: The machine helps increase the operational efficiency of Thanh Linh Restaurant.

Research objectives

- Study theoretical foundations: Investigate the theoretical basis and explore existing automatic spring roll wrapping machines available in the market

- Develop a high-quality automatic spring roll wrapping machine: Successfully research and develop an automatic spring roll wrapping machine with high productivity and quality, ensuring aesthetics and food safety

- Automate the mixing and stuffing mechanism: Successfully develop an automatic mixing and releasing mechanism

- Manufacture according to design: Produce the machine based on the proposed design, ensuring working efficiency.

Objects and Scope of research

- Spring rolls in the food industry

- Principles of automatic rice paper and stuffing supply

- Research and design of the electrical and sensor system

- Research, design, and manufacture the mixing and releasing mechanisms of the stuffing unit in the automatic spring roll machine

- Design and simulation software: SOLIDWORKS 2021, AutoCAD Mechanical 2021, Creo Parametric 8.0.0.0, ANSYS 2022, AutoCAD Electrical 2021, GX Works2, MDSolids 4.0, CADe-SIMU

- Stuffing composition: minced chicken, carrots, cabbage, and green onions mixed with spices

- Mixing volume ranging from a minimum of 500g to a maximum of 10kg

- Stuffing formed in rectangular shapes, measuring 120mm in length and weighing 60g.

Research methodology

To conduct this research, the authors employed the following methods:

A comprehensive literature review will be conducted by examining diverse sources, including books, textbooks, and reputable online articles, alongside catalogs from global manufacturers This approach aims to identify the most effective control and processing plans for the machine.

- Experimental method: Conduct automated trial runs, followed by sampling, measuring, calculation, and comparison between experiments

After conducting consultations, reviewing relevant literature, and gathering data on the dimensions, shape, and properties of stuffing, along with customer requirements, we will analyze data pertaining to existing machinery in the market.

The primary objective of this project is the modeling method, which enables the team to revisit previously acquired knowledge and enhance their practical experience This approach facilitates hands-on machining and assembly tasks while also uncovering theoretical errors that may have gone unnoticed before.

Structure of the graduation thesis

OVERALL

Introducing the spring rolls

Spring rolls, a beloved dish in Vietnamese cuisine, also referred to as "nem ran" or "cha ram," are primarily made with minced pork or shrimp, offering a delightful combination of flavors To enhance their taste, spring rolls can include additional ingredients such as mushrooms, onions, green onions, tofu, and seasonings like fish sauce, pepper, salt, sugar, and MSG.

The process of preparing spring rolls starts with combining the ingredients to create the filling mixture A sheet of rice paper is then laid flat, and a generous amount of filling is placed at the bottom The rice paper is folded over the filling from both sides to form a cylindrical shape and rolled tightly Finally, the spring rolls are fried in hot oil until they achieve a golden color and a crispy texture.

Figure 2.1: Northern spring rolls Figure 2.2: Southern spring rolls

This dish is typically accompanied by fresh greens like salad, white cabbage, or other raw vegetables, complemented by a sweet and sour fish sauce Serving styles and combinations vary based on individual tastes and culinary preferences Spring rolls are not only a delicious treat but also a popular choice at parties, restaurants, and family gatherings.

Spring rolls have become a beloved staple in international cuisine, particularly within East Asian and Vietnamese culinary traditions In metropolitan areas across the United States, Canada, Australia, and Europe, numerous Asian restaurants feature spring rolls on their menus Additionally, many international restaurant chains have embraced spring rolls to cater to diverse culinary preferences Today, spring rolls can be found in Vietnamese eateries, multi-cuisine restaurants, and even fast-food outlets in various Western nations.

Figure 2.3: Menu at Thanh Linh restaurant (Investor)

Figure 2.4: Spring rolls at the Thanh Linh restaurant

Thanh Linh, a popular Vietnamese restaurant in Peoria, Illinois, attracts a diverse clientele, including civil servants, American workers, immigrants, and the local Vietnamese community Renowned for its authentic Vietnamese cuisine, the restaurant offers favorites like pho, grilled-pork noodles, beef noodles, and especially its delicious Vietnamese spring rolls With hundreds of customers visiting daily, Thanh Linh is a highly-rated dining destination in the area.

7 the restaurant has to accommodate an average of about 5.000 spring rolls per week, even during holidays, customers can eat and order up to 10.000 pieces [19]

Spring rolls are a versatile dish that can be easily paired with various cuisines, making them a popular choice in bars and restaurants They can be combined with dishes like sushi and salads to create unique culinary experiences The diverse range of ingredients used in Vietnamese spring rolls appeals to many diners Additionally, in countries like France and Italy, local ingredients are incorporated into spring rolls, which may be wrapped in bread or fried dough instead of the traditional rice paper or pho noodles, resulting in exciting new flavors and textures.

The introduction and promotion of Vietnamese spring rolls at cultural events, festivals, and food fairs provide a unique opportunity for both locals and tourists to experience and savor the diverse flavors of spring rolls alongside other traditional Vietnamese dishes.

Spring rolls have become an essential element of international cuisine, cherished by consumers globally Their popularity is attributed to the flexible combination of diverse culinary traditions, showcased through restaurants and cultural events.

Properties of the spring rolls filling

According to customer requirements, the spring roll filling includes ingredients such as chicken, carrots, cabbage, wood ear mushrooms, vermicelli, green onions, eggs, and various spices

Figure 2.5: Main ingredients for spring rolls filling: Chicken, carrot, cabbage

- Shape and Size: The spring roll filling is usually cylindrical The size of the filling should satisfy customers and facilitate the rolling process

- Firmness: The filling needs to have appropriate firmness so that when the spring roll is made, the filling remains tasty and does not dry out

2.2.3 Filling role for spring roll

The filling of spring rolls plays a very important role in the dish, from flavor and nutrition to texture and culinary culture

- Flavor: The filling determines the taste of the dish with a blend of meat, seafood, mushrooms, and spices A rich, balanced flavor is crucial for creating a delicious dish

- Nutrition: The filling provides many nutrients such as protein from meat and seafood, fiber from vegetables, and vitamins from mushrooms The combination of ingredients ensures a nutritionally balanced meal

- Texture: The filling keeps the spring rolls crispy and provides a rich texture It shouldn't be too wet or too dry to maintain shape and prevent breaking during frying

- Tradition and Culture: The filling reflects the richness and diversity of Vietnamese cuisine, combining many distinctive ingredients and being inherited and improved through generations

- Creativity: The filling can be customized according to taste and preferences, adapting to local ingredients, and creating unique and innovative variations in cuisine.

Components of an automatic spring roll rolling machine

To perform the spring roll rolling operation, an automatic spring roll rolling machine requires basic structural components as presented in the diagram in Figure 2.6

Figure 2.6: The basic structural components of the spring rolls making machine

2.3.2 Functions of each structural component a Releasing structure

Moistened rice paper is placed on a manual conveyor belt, which transports it to the feeding unit that evenly mixes the filling ingredients The filling mixture is then pressed into a mold and shaped by a screw shaft Once the rice paper reaches the optimal position for folding, the filling is pressed onto its surface, allowing it to proceed to the next stage.

As the rice paper and filling advance to the folding unit, a folding piece elevates and flips the filling, allowing one end of the rice paper to be folded, thereby shaping the corner of the roll This process utilizes an edge rolling structure for efficient assembly.

After folding, the rice paper and filling are processed through a rolling shaft on either side of the conveyor belt, which flattens the edges of the roll to prepare for the subsequent stage This edge pressing structure ensures a smooth and uniform finish for the product.

After the edges are flattened on both sides, the spring roll passes through the edge pressing unit to create a neat fold pattern for the side folding stage

The rice paper, after undergoing flattening and folding in earlier stages, transitions to the side folding unit, where its edges are sequentially folded inward This process is facilitated by two folding pieces that move upward from beneath the conveyor belt, ensuring precise shaping of the rice paper.

Once folded, the rice paper is transferred to the shaping unit, where a downward-moving cylinder exerts pressure to flatten it This process ensures that the filling remains secure and does not spill out during the rolling stage.

Once the rice paper and filling have been prepared, they are transported to the rolling unit, where a mesh panel on the conveyor belt ensures the rice paper is rolled into a perfect round shape without tearing or spilling the filling This automated process finalizes the spring roll preparation, making them ready for frying or storage.

Introducing mixing and releasing structure

Operating diagram of the mechanism:

Figure 2.7: Operating diagram of the mechanism

Mixing mechanism and releasing mechanism are two crucial components in spring roll machines, playing significant roles in efficient spring roll production Here's an introduction to each:

The mixing mechanism plays a crucial role in achieving a uniform blend of ingredients for spring roll fillings, including meat, vegetables, and other components It ensures even distribution, enhancing the overall quality and consistency of the mixture.

The mixing mechanism generally consists of a mixing tank equipped with shafts and blades, where ingredients are added to the tank Once the components are introduced, the activated blades or shafts efficiently mix and combine them thoroughly.

- Flexibility: Automatic spring roll machines often feature adjustable mixing mechanisms to accommodate various types of ingredients and different mixture ratios

- Function: The releasing mechanism is responsible for delivering the mixed filling into the spring roll rolling process

- Design: It usually consists of a metering and pushing system designed to accurately supply the required amount of filling to the rolling area

- Adjustability: The releasing mechanism can be adjusted to control the supply rate of ingredients, ensuring a continuous and uniform rolling process

- Automation: Integrated with automatic control systems, the releasing mechanism adjusts the releasing speed based on preset parameters to optimize production efficiency.

Quality standards for spring rolls

- Ingredients: Choose fresh ingredients that are free from unpleasant odors and black spots Use suitable ingredients to ensure the filling achieves the desired density

- Flexibility: The rice paper should have moderate flexibility to facilitate easy rolling without breaking or tearing

- Moisture Content: The rice paper should not be too moist or too dry, as this will affect the rolling process and compromise the density of the spring rolls

- Consistency: Ensure the filling is evenly distributed to maintain uniformity in the rolls

- Tightness: Roll the spring rolls tightly enough to hold the filling together without being too loose, which can cause the rolls to fall apart during cooking

- Size and Shape: Maintain consistent size and shape for all rolls to ensure even cooking

Following these standards will help achieve high-quality spring rolls that are well-formed, consistent.

Government standards on food safety and hygiene [29]

2.6.1 General food safety and hygiene regulations

- Personal hygiene regulations: Employees must comply with personal hygiene regulations, such as washing hands thoroughly before handling food, wearing protective gear, and maintaining cleanliness

- Ingredient management: Standards regulate the management of ingredients from purchasing, storage, to safe and uncontaminated use

Maintaining high sanitation standards is crucial in food safety, as it ensures that work areas, equipment, and surfaces are regularly cleaned to prevent the spread of bacteria and contaminants Additionally, strict regulations on the separation of various food types help avoid cross-contamination, further enhancing food safety practices.

- Temperature regulations: Standards on temperature ensure that food is stored and transported at safe temperatures to prevent the growth of harmful bacteria

2.6.2 Specific food safety regulations for spring roll production

- Ingredient management: Standards regulate the selection and management of ingredients used in spring rolls to ensure quality and safety Ingredients must comply with food safety regulations and be uncontaminated

- Production Process: Regulations on the spring roll production process ensure hygiene and safety This includes the selection and preparation of ingredients, the rolling process, cooking temperatures, and storage regulations

Maintaining high sanitation standards for spring roll rolling machines and related surfaces is crucial to prevent bacterial contamination Additionally, regulations ensure proper separation between different stages of the spring roll production process to eliminate the risk of cross-contamination.

- Safety and hygiene evaluation: Regulations may require inspection and evaluation of the hygiene and safety of spring roll rolling machines to ensure compliance with food safety and hygiene standards

2.6.3 Regulations on the manufacture of food processing machines and lines

When manufacturing food processing machines and lines, it is essential to use safe materials that adhere to hygiene and safety regulations to prevent food contamination Compliance with standards often necessitates the use of stainless steel or other easily sanitized materials, ensuring the integrity of the food processing environment.

- Reasonable design: The design of machines and lines must ensure safety, ease of cleaning, and convenience for use and maintenance

- Inspection and maintenance: Food processing machinery and lines must be regularly maintained to ensure efficient and safe operation Regular inspections are also necessary to identify potential failures and hazards

=> In this project, our group used FDA and NSF standards to refer to manufacturing materials.

Spring rolls making process by hand

For generations, wrapping spring rolls has been a cherished tradition during the Lunar New Year, fostering a festive and familial atmosphere This activity symbolizes the skill, care, and meticulousness of Vietnamese women, as creating perfect spring rolls requires significant time and effort To ensure a delicious meal, the spring rolls must be tightly and fully wrapped, allowing them to fry evenly, become crispy, and avoid absorbing excess oil.

The global popularity of spring rolls has led to a surge in demand at restaurants, making manual wrapping insufficient to meet the required quantity and consistent quality As a result, traditional hand-wrapping is now primarily suitable for home preparation or small eateries with limited customer bases.

The steps to roll spring rolls by hand include:

1 Place a dampened rice paper on a flat surface, then place an amount of spring roll filling on the bottom part of the rice paper

2 Roll up from the bottom corner a bit to wrap the filling in the rice paper

3 Fold the two sides of the rice paper toward the center over the filling

4 Continue rolling from the bottom to the top so that the filling is completely enclosed inside

5 When you have rolled a bit, apply a little egg to the excess part of the rice paper to seal it

6 Continue rolling until you have used up all the filling or rice paper

Figure 2.9: Spring rolls rolling by hand process

Figure 2.10: The steps to roll spring rolls by hand

Semi-automatic spring roll rolling machine

The spring roll rolling machine, a fully "Made in Vietnam" product, has been available for some time but has yet to gain widespread popularity, despite its potential to revolutionize the process of rolling spring rolls through automation.

The product features a straightforward packaging design that lacks refinement and aesthetic appeal Additionally, its assembly components are not well-engineered, resulting in a challenging experience when it comes to assembling and disassembling the item smoothly.

Figure 2.11: Spring rolls rolling revice [31]

Figure 2.12: Semi-automatic spring roll rolling machine

This innovative machine enables users to quickly and efficiently roll beautiful, tight spring rolls However, as it is relatively unfamiliar to many, new users may find it challenging to operate Taking the time to read and follow the instructions is essential for mastering the technique and producing standard spring rolls.

Figure 2.13: Putting the filling onto the rice paper [31]

While the spring roll machine can expedite the rolling process, it does not significantly save time compared to hand-rolling Users still need to manually spread the rice paper and place the filling, with the machine only assisting in the rolling step Although the machine may roll slightly faster under optimal conditions, the setup, including adjusting the machine and preparing the rice paper, demands time, skill, and patience.

Figure 2.14: Pull the push bar to roll the fabric [31]

While this machine effectively produces uniformly rolled and visually appealing spring rolls, it has several notable drawbacks Users may find it difficult to learn and operate, as it does not function smoothly and fails to save time Additionally, the spring rolls produced may lack taste and visual appeal, and the machine can be challenging to clean.

Figure 2.15: Spring rolls wrapped by the semi-automatic machine are unattractive due to torn rice paper [31]

Spring rolls often become loose due to a rolling mold that is too large, even at its smallest setting Additionally, the ends of the spring rolls can loosen because they are not folded and compressed as they would be when rolled by hand As a result, these fried spring rolls tend to absorb excess oil, leading to an unsatisfactory taste.

After use, hand-rolled items require only the washing of the tray or plate, while using this machine necessitates disassembling its parts for thorough cleaning, including the rolling fabric.

Automatic spring roll making machine models on the domestic market

Many Vietnamese companies have effectively developed and launched automatic spring roll wrapping machine lines, which have gained positive feedback from various production facilities Here are some models of domestically produced automatic spring roll making machines currently available in the market.

2.9.1 Automatic spring roll making machine of Thien Phu company

Thien Phu's automatic spring roll making line is designed for large-scale production, making it perfect for restaurants and packaged sales This advanced machine mimics the hand-rolling technique by folding corners over the filling and tightly rolling spring rolls, effectively replacing 2-4 workers in the process Capable of producing multiple items simultaneously, it can also integrate with frying and freezing systems for efficient preservation.

Figure 2.16: Automatic spring roll making machine from Thien Phu company [27] Features of Thien Phu Company's Spring Roll Production Line [27]:

- The fully automatic spring roll production line is made of 304 stainless steel, with a beautiful appearance, clean production process, hygienic, and meets European standards

- The rollers are made of alloy steel, with high hardness and are not easily deformed

- The induction heating system has fast heating speed, even heating, and is more durable

- The size and shape of the spring rolls can be customized, allowing for different fillings and diamond-shaped forms

- Multiple fillings such as vegetable filling, meat filling, and fruit filling, which have good adhesion and do not easily spill out

- The sensor probe can accurately detect the position of the spring roll and fold it

- The PLC control panel is simple and convenient to operate

Table 2.1: Technical specifications of Thien Phu company's spring roll making machine

Spring Roll Production Line GG-CJX5000 [21]

Name Dimension (mm) Capacity (mm)

- The machine can adjust the speed of the conveyor belt

- The processes are automated from start to finish

- The spring rolls produced by the rolling machine have uniform shape and size with even thickness

- This machine has stable performance and a unique mechanism

- Ensures food safety and hygiene

- Large weight makes it difficult to transport

- Large capacity can create noise when operating

- Only suitable for large-scale production facilities

2.9.2 Automatic spring roll making machine from ANKO Vietnam company

The ANKO Vietnam automatic spring roll making machine offers a fully automated solution, capable of producing 2,400 spring rolls per hour This advanced machine streamlines the entire process, from mixing the batter and filling to baking, cutting, and rolling, ensuring consistent quality and taste that rivals handmade spring rolls Trusted by restaurants and food companies across the USA, Canada, Germany, China, and Jordan, ANKO's equipment is the ideal choice for efficient spring roll production.

Figure 2.17: Automatic spring roll making machine from ANKO Vietnam company [12]

- Product dimensions: 25-30 (Diameter) x 100 (Length) mm

- Product weight: 40-50 g (varies depending on filling ingredients)

- Air consumption: 480 L/min (6 kg/cm2)

- Easy to clean, repair, and maintain

- Fully automatic from supplying rice paper to final product output

- Adjustable rice paper size during operation

- The rolling device is designed to mimic the hand-wrapping process to tightly roll each spring roll After frying, the spring rolls are crispy without being greasy

- Ensures food safety and hygiene

- The machine is heavy, making transportation and placement difficult

- The machine generates noise during operation

- Only suitable for large-scale production facilities.

Automatic spring roll making machines on the international market

2.10.1 Automatic spring roll making machine from Gelgoog company (China)

Spring rolls are a beloved dish not only in Vietnam but also globally, with a significant following in China The demand for spring rolls in Chinese restaurants and factories has led to a need for large-scale production Gelgoog Company has effectively developed automatic spring roll making machines that boast numerous exceptional features, catering to this growing market.

The Gelgoog Company's automatic spring roll making machine efficiently replaces the labor of 2-4 employees by performing pressing, filling, and shaping in one streamlined production line Capable of producing multiple spring rolls simultaneously, its output varies based on the size of the rolls Additionally, this versatile machine can be seamlessly integrated with frying and quick-freezing lines for enhanced processing efficiency.

Gelgoog's spring roll production line features a state-of-the-art design, utilizing SUS304 stainless steel and high-strength aluminum alloy A6061 to guarantee food safety and hygiene This production line offers an excellent solution for producing spring rolls that match the quality and flavor of handmade varieties Additionally, it is user-friendly, making assembly, cleaning, and maintenance straightforward.

21 Figure 2.18: Automatic spring roll making machine from Gelgoog company [17]

Figure 2.19: Production process of Gelgoog's automatic spring roll making system [17]

Table 2.2: Technical specifications of Gelgoog's automatic spring roll making machine

Model GG-CJX3000 GG-CJX5000 GG-CJX7000

Air Pressure 0.6-0.8mpa 0.6-0.8mpa 0.6-0.8mpa

Length: 9 cm; Diameter: 2.6 cm; Weight: 30-40g

- High customization according to product requirements

- Stable and synchronized operation of the production line

- Saves 30-70% energy compared to other machines on the market

- Easy to clean and maintain

- High cost, ranging from $40,000 to $80,000

- Bulky size, requiring a lot of space for installation

- Only suitable for large-scale production

2.10.2 Automatic spring roll making machine from Cabinplant Inc (Denmark)

Cabinplant's innovative solutions in spring roll processing offer significant business benefits for large-scale food factories, reducing costs while ensuring the highest quality of spring rolls for consumers

With more than 20 years of expertise in food processing equipment research and manufacturing, Cabinplant offers tailored solutions to meet partner needs Their automatic spring roll making machine efficiently produces between 60 and 240 spring rolls per minute, accommodating various fillings and output capacities for diverse processing lines.

Figure 2.20: Automatic spring roll making machine from Cabinplant Inc [14]

Figure 2.21: Automatic making line of the machine [14]

Table 2.3: Technical specifications of Cabinplant Inc.'s spring roll making machine Dim (mm) Single lane Double lane Triple lane Four lane Large drum

- Only suitable for large-scale production facilities

- Complex machine structure, difficult to repair.

THEORETICAL BASIS

Theoretical basis of the material mixing process

Mixing involves combining various materials to create a homogeneous mixture, ensuring a uniform distribution of molecules within each component This process is facilitated by external forces that rearrange the materials, ultimately improving heat and mass exchange processes.

3.1.2 Uniformity of mixture after mixing

Uniformity of mixture refers to the quantitative measure of the mixing process, defined by the mass ratio of a component in the analyzed sample compared to the specified mass of that component in the mixture When mixing substance A with mass a and substance B with mass b, a homogeneous mixture AB is formed, consisting of the components A and B.

In an ideal material mixture, the concentrations of components CA and CB should be uniform across all volume parts However, variations in the mixing process often lead to differences in these concentrations A smaller discrepancy indicates a mixture that is closer to the ideal state To evaluate the uniformity of the actual mixture, the "Mean Squared Deviation" can be employed as a measurement tool.

Vi of the mixture contains component A as CiA, and component B as CiB, then the "Mean Squared Deviation" of the actual mixture will be:

CA, CB: component A and component B in the ideal mixture;

CiA, CiB: component A and component B in the volume sample; Vi;

=> Therefore, smaller values of SA, SB indicate higher uniformity of the mixture, closer to the ideal mixture The values of SA and SB depend on the mixing time [4]

Some mixing machines

1: Tank 2: Upper tube 3: Auger shaft 4: Lower tube 5: Drain valve 6: Drain valve 7: Drive assembly Figure 3.1: The structure of a vertical auger mixer [4] b Operating principle:

The material is introduced into the feeding chute and lifted by an auger Upon reaching the top, paddles push the material outward, allowing it to descend into the conical body This process continues, circulating the material until a uniform mixture is achieved Once mixing is complete, the material is discharged through the outlet door.

1: Blender 2: Shaft 3: Drive assembly 4: Tank Figure 3.2: The structure of blender mixing [4] b Operating principle:

When activated, the machine's rotating shaft and mixing blades create a flow within the drum The mixing blades generate centrifugal and pushing forces, drawing components toward the drum's center and then propelling them outward This continuous movement ensures that all components maintain contact, promoting thorough mixing throughout the process.

1: Tank 2: Drive assembly 3: Machine frame Figure 3.3: The structure of rotary drum mixing [4] b Operating principle:

The rotary drum mixer operates by rotating a mixing drum and utilizing internal blades or a shaft Upon activation, the blades generate centrifugal force, pushing mixing materials like powder, liquid, or granules outward from the center This force creates a flowing stream within the drum, lifting materials upward and allowing them to fall, resulting in an effective mixing process.

Theoretical basis of quantitative methods

Quantitation is a precise measurement technique essential for various materials, guided by technological, food, and economic standards The accuracy level required can vary significantly based on these factors Quantitative objects encompass a wide range of forms, including loose materials, low-viscosity liquids, viscous substances, dense items, flexible materials, and pasty textures.

In food production, accurately measuring specified amounts of ingredients and quantifying additional materials and finished products is crucial Proper quantification ensures the effective implementation of technological processes, adherence to prescribed mixing methods, and the correct dosing of finished products.

The process of quantifying bulk materials is usually carried out in two ways [9]:

Bulk materials are supplied in a continuous and consistent manner, allowing for precise measurement of the quantity delivered This measurement can be achieved by assessing the volume or mass of the material flowing through the machine within a specific time frame.

The quantification of each batch is primarily achieved through an automated weighing process Once the designated amount is loaded, the automatic system seals the feed line and extracts the product from the machine The supplied quantity is defined by the volume or mass of the material in a precisely weighed batch.

The choice of measuring method and type of measuring machanism depends on the physical properties and particle size of the measured product, including [9]:

- Size, volume, mobility, moisture, adhesion, clumping, ability to form large blocks and dispersion of the bulk product

- Density, viscosity, stickiness, presence of suspension particles for liquid products

- Volume, consistency, stickiness, flexibility, elasticity for dough products.

The quantitative method

Figure 3.4: Screw feeder measuring machine [9]

The screw measuring device is a medium-precision tool designed for bulk material dosing Its structure resembles that of a conveyor screw, though it is typically smaller and shorter When the metering screw rotates at a consistent speed, it delivers a constant supply quantity over time To modify the supply amount, the rotation speed of the metering screw can be adjusted using a stepless speed converter.

The feed screw can be placed horizontally or at an angle

The supply of material from the metering screw is inconsistent over time, primarily due to the screw's design and the challenges associated with maintaining a continuous flow of bulk material.

Figure 3.5: Table feeder measuring machine [9] b Working principle

The measuring disc is a horizontal rotating disc, above which is the material hopper

The fixed plow is positioned on the surface, with the electric motor located beneath it Material from the hopper descends to the rotating disc, where it interacts with the plow and subsequently falls downwards The flow of material is regulated by adjusting the movable feeding tube that encases the discharge tube of the hopper or by altering the plow's proximity to the rotating disc.

The efficiency of a measuring machine is influenced by several key factors, including the product volume on the disc, the height and alignment of the plow bar, and the disc's rotation speed.

Measuring pots are used to release and quantify small granular and dry powder materials They ensure sufficiently precise feeding when the productivity is relatively large

Figure 3.6: Conveyer feeder measuring machine [9] b Working principle

The quantification conveyor, resembling a cargo conveyor but shorter in design, is specifically engineered for accurate material measurement rather than transportation It features a material hopper positioned above the belt to ensure uniform delivery An adjustable shield at the feeding hopper's outlet regulates the supply quantity, while additional shields along the conveyor's sides create a rectangular cross-section of the product layer, enhancing measurement precision.

To streamline the measurement process, a sensor system is typically implemented to monitor fluctuations in the weight or volume of materials on a conveyor When there is a change in the material's weight on the belt, the sensor system adjusts the vibration frequency of a vibrator positioned accordingly.

34 exit of the feeding hopper, correspondingly changing the amount of supply or changing the number of revolutions of the conveyor pulley

Figure 3.7: Controlled partial quantification procedure [9]

The working cycle of a particle quantification machine featuring a microprocessor begins with a rapid discharge phase, where the system quickly reaches 97% of the required material amount Once this threshold is met, the discharge door closes, causing the material flow to slow down When the weight of the material is deemed sufficient, the discharge door seals, and the material release door opens, allowing the complete amount of material to be poured into the packaging.

Partial quantification involves dividing a material's original mass into equal volumes or weights for analysis This process utilizes equipment that operates in cycles, which can be manually controlled alongside mechanical devices or automatically managed by microprocessor systems.

The partial quantification machine has a measuring mold that is filled with pappy material and removed by force.

Theoretical basis for choosing rice paper

- The rice paper requested by the investor is beef rice paper made from wheat flour

- Flexibility: Rice paper needs to have moderate flexibility to easily roll the rolls without breaking or tearing

To achieve the perfect spring rolls, it's essential to maintain the right humidity level for rice paper; it should neither be too moist nor too dry, as this can impact the taste and rolling process, compromising the tightness of the rolls For optimal storage, consider keeping rice paper in the freezer to preserve its quality.

- Shape: Rice paper used to make spring rolls is usually square and 20x20mm in dimensions The right dimensions will make rice paper easier to roll

Figure 3.8: The dimensions of rice paper

DIRECTIONS AND SOLUTIONS FOR DESIGNING THE MIXING AND

Design parameter

The mission of this project is to design, calculate, and manufacture the mixing and filling mechanism for a restaurant-scale automatic spring roll making machine Key considerations include the use of standard household electric power in the United States (110V-60Hz), a manageable compressed air supply, and the selection of manufacturing materials that ensure food safety and hygiene at a reasonable cost Based on these criteria, our team has established the design parameters for the machine.

Table 4.1: Expected design parameters of the machine

Name Restaurant-scale automatic spring rolls making machine

Materials Stainless Steel (INOX 304), POM plastic material

Directions, solutions and selection of design plans

Figure 4.1: Working position of the releasing structure on the automatic spring rolls making machine

Figure 4.2: Principle diagram of the machine

Figure 4.3: Working structures in the releasing cluster

Table 4.2: Working function of structures

STT Working structures Working functions

1 Mixing structure Mix and scrape the mixture of ingredients to make the spring roll filling

2 Auger-filler Eject the filling into the measuring-mold

3 Mold pushing cylinder Push the mold cavity move to forced-pushing position

4 Measuring-mold Measure the filling according to the specified weight

5 Forced-pushing Push the filling falling from the measuring mold onto the rice paper on the conveyor

Table 4.3: Classification of manual and automatic steps

Put the mixed filling ingredients into the hopper

Mix and scrape the filling Eject the filling into the mold cavity Measure the filling mass Push the filling falling on the rice paper

4.2.1 Principle of operation of structures in releasing cluster

- Mixing structure: Mix and scrape the mixture of ingredients that easily fall to the bottom of the hopper

- Auger-filler: After being mixed well, the auger-filler will be extruded and pressed into the measuring mold continuously

Figure 4.5: Auger-filler in hopper-pipe

The measuring-mold structure utilizes an auger-filler to transport the filling from the top to the bottom of the hopper This process ensures that the filling is compacted and precisely shaped to fit the mold cavity, which is specifically designed and manufactured to meet the customer's unique specifications.

Figure 4.6: The mold cavity when closed Figure 4.7: The mold cavity when opened

The mold pushing cylinder plays a crucial role in the filling process Once the mold is filled, the rice paper moves along the conveyor to the designated position The cylinder then pushes the mold cavity outward, allowing the filling to drop onto the rice paper After this, the cylinder retracts, returning to its original position to prepare for the next cycle of operation.

Figure 4.8: Mold pushing cylinder structure

Forced-pushing is a process where, after the mold cavity is filled, the cylinder forces the contents to drop onto rice paper on a conveyor Subsequently, the cylinder returns to its original position, allowing the mold cavity to retract.

4.2.2 Analyzing the directions and selecting design plans a Choosing the mixing mechanism

- Able to mix the filling ingredients, can scrape stuck ingredients around the walls of the hopper

- Able to eject the filling into the measuring mold

- Ensure moderate capacity of 10kg

Option 1: Fixed hopper, rotating shaft including mixer-wing and auger-filler

Option 2: Rotating hopper, fixed mixing shaft

Putting the filling into the hopper, the mixing wing will rotate to stir the ingredients, then the auger-filler will eject the filling into the measuring mold

The filling ingredients are placed into the rotating hopper, where the mixing wing, fixed to the shaft, thoroughly blends them Subsequently, the auger-filler dispenses the well-mixed filling into the measuring mold.

Suitable for small and medium capacity requirements

Easy to design and manufacture

Easy to install and repair

Suitable for large-scale production with large material capacity

Defect Not suitable for industrial scale production

Suitable for industrial scale production

Difficult to design and manufacture Table 4.4: Choosing the mixing mechanism

Figure 4.10: The mixing mechanisn for option 1 [3]

Figure 4.11: The mixing mechanisn for option 2

Conclusion: Based on the capacity requirements and especially the customer's production scale, we choose option 1 for manufacturing

To fabricate a storage hopper that meets the required capacity, ensure secure installation with the measuring mold Next, attach the mixer-wing and auger-filler to the rotating shaft, which is then installed with a motor positioned above the hopper for optimal operation.

42 rotating shaft through a coupling for easy disassembly and cleaning The shaft is supported and fixed by thrust ball bearings b Choosing the measuring method

- Measuring the correct amount of filling mass required by the customer

- Match the size of the pressed filling to the size of the rice paper to avoid bulging or missing filling during the rolling process

- The shaped filling has uniform output dimensions

Option 1: Measuring by screw feeder method (stated in 3.4.1)

Option 2: Measuring by table feeder method (stated in 3.4.2)

Option 3: Measuring by the partical quantification method (stated in 3.4.4)

Using a screw placed horizontally to directly eject the filling into rice paper

Using the rotating disc, the filling flows down the rotating disc and comes into contact with the plow and then falls onto the rice paper

An auger-filler positioned vertically is utilized to dispense and compress the filling into a mold, shaping it as required before it is released onto rice paper.

Ensuring accurate feeding when productivity is high

Suitable for measuring small granular and dry powder materials

Ensuring accurate feeding when productivity is high

Easily measure the filling with high accuracy for small and medium production scales

Large in size when manufactured

Unable to produce the uniform filling shape and mass

The method has a complex structure due to the need to design a measuring mold

Table 4.5: Choosing the measuring method

Figure 4.12: Screw feeder Figure 4.13: Table feeder Figure 4.14: Partical quantification

Conclution: For suitable the machine production scale and actual using as well as economics, we choose option 3 for manufacturing

To design and manufacture a measuring mold tailored to customer specifications, we focus on achieving the desired filling volume while integrating an auger-filler for effective ejection This process ensures that the filling is accurately positioned on the rice paper, facilitating the subsequent rolling stages The mold features a cavity that can be easily pushed out and pulled in using a push cylinder, with dimensions calculated to match the customer's filling volume requirements and to create shaped fillings that roll effortlessly Additionally, selecting the appropriate materials for the measuring mold is crucial for optimal performance and durability.

- The mold is highly durable and resistant to abrasion

- Having reasonable manufacturing and processing costs

- Ensuring food safety and hygiene

Aluminum is a metal widely used in industry, is light in weight and highly resistant to corrosion

Teflon plastic is a high- density engineering thermoplastic with the original English name PTFE, short for Poly TetrafloEtylen (Polytetrafluorethylene)

POM (Polyoxymethylene) is an engineering thermoplastic widely used in many industries

Light-weight High corrosion resistance

No rust Easy to process and cutting

Easy to clean Not transformed into toxic substances Good weather resistance Ensuring the best hygiene and food safety Able to control

Good heat resistance Fire protection Great hardness Resistant to most chemicals

No change in state between -190°C and 300°C

Friction coefficient is very low

High hardness High abrasion resistance Wide operating temperature range (-40°C

~ 120°C) Good impact resistance Low friction coefficient Resistant to water and chemicals

Most reasonable price (6,500,000 VND/plate)

High price (8,500,000 VND/A6061 aluminum plate)

Easily deformed when impacted to external forces

The price is very high compared to POM and aluminum alloy

Surface gets dirty easily Easily deformed when machining or cutting High expansion rate when weather condition changes

Table 4.6: Choosing materials for manufacturing the measuring mold

Figure 4.15: Materials options for manufacturing the measuring mold

*Plate dimentions: 1000mm x 1000mm x 30mm

*Material costs are referenced andsynthesized on the market

Conclution: The cost requirements have been set by the customer, we choose option 3 for manufacturing

The machining of POM plastic molds is tailored for each component using CNC technology, ensuring precise assembly Key parameters for the filling mass are calculated, alongside optimal mold cavity dimensions, to minimize weight discrepancies and achieve uniform output shapes This precision is essential for the seamless operation of the entire automatic spring roll rolling machine line Additionally, selecting an effective mold cavity pushing mechanism is crucial for enhancing efficiency.

- The mold cavity ejection mechanism must operate stably and smoothly

- Easy to design, manufacture, assemble and control

- The structure is highly durable, does not require too strict maintenance

Option 1: The mold cavity is pushed and pulled by a pneumatic cylinder

Option 2: The mold cavity is pushed and pulled by a rack and pinion mechanism Action

Using a pneumatic cylinder to pull and push the mold cavity into and out of the measuring mold

Using a rack and pinion mechanism to pull and push the mold cavity

Simple structure Easy to design and manufacture Easy to install

High traction Stable push-pull movement

Defect Not suitable for heavy molds Complex structure

High manufacturing costs Table 4.7: Choosing the mold cavity pushing mechanism

Figure 4.16: The mold cavity pushing mechanism for option 1 Figure 4.17: The mold cavity pushing mechanism for option 2

Conclution: The structure does not require high tensile force, it must have a low price and be easy to manufacture assembly and maintenance, so we choose option 1 to manufacture

To install a pneumatic cylinder within the mold cavity for efficient push-pull motion, ensure it is securely connected via a threaded fastener, facilitating easy disassembly and cleaning post-use Additionally, selecting the appropriate material for the manufacturing of the push-head in the forced-pushing structure is crucial to meet technical requirements.

- Ensuring food safety and hygiene

Option 1: POM Option 2: PTFE (TEFLON)

The forced-pushing mechanism is activated, the cylinder pushes the POM plastic block down, forcing the filling to fall onto the rice paper on the conveyor

The forced-pushing mechanism is activated, the cylinder pushes the Teflon plastic block down, forcing the filling to fall onto the rice paper on the conveyor belt

Advantage Low price to buy material Anti-adhesion ability

The filling easily sticks to the surface of push-head

Easily deformed when machining or cutting

High price to buy material

Table 4.8: Choosing material for manufacturing the push-head of forced-pushing structure

Conclution: Due to the small dimensions of the push-head, we can choose to make it with

Teflon material to both ensure material costs, have good anti-adhesion ability according to the requirements and ensure food hygiene and safety Choosing option 2 to manufacture

The push-head, crafted from Teflon plastic, is designed with precise dimensions to ensure the efficient operation of the forced-pushing mechanism This design prevents the filling from adhering to the push-head surface, thereby eliminating delays in the filling's descent and maintaining accurate positioning on the rice paper.

4.2.3 Summary of elected design options

Mixing-structure Fixed hopper, rotating shaft including mixer-wing and auger-filler X

Measuring by the partical quantification method X

Material of measuring mold POM material X

The mold cavity is pushed and pulled by a pneumatic cylinder X

Table 4.9: Summary of selected design options

DESIGN AND CALCULATION

Calculation and design of a molding cage

Length of a spring roll: l = 120 (mm)

The design of mold shapes can differ based on their specific applications In this research, we opted for a rectangular box mold, as it enhances the efficiency of the spring roll wrapping process.

The volume of the mold V (m 3 ) is determined by the formula:

𝟕𝟒𝟏 = 𝟖, 𝟎𝟗𝟕𝟐 𝟏𝟎 −𝟓 (𝒎 𝟑 ) Preliminary design of the mold shape

Figure 5.1: Preliminary design of the mold shape The volume of the mold V (m 3 ) is determined by the formula for calculating the volume of a rectangular box as follows

• a: side length of the mold (mm)

Calculation of screw

Constant load in one direction

Working height of the screw: H = 100 (mm)

The screw capacity Qt (tons/h) is followed by the formula:

• S: The pitch of the screw (m)

The mixing frame mechanism features a significantly larger radius than the screw conveyor, necessitating a careful selection of shaft rotational speed for optimal durability Research indicates that in environments with material densities below 1000 kg/m³, the rotational speed of the mixing frame mechanism is generally low, typically between 20 RPM and 40 RPM.

• c: Angle coefficient β (degrees) of screw

Substituting into the formula 5.3, we have:

Choosing the flight diameter D = 38 (mm)

The optimal screw blade diameter to casing diameter ratio is between 0.95 and 0.98, as indicated in the document [2] Based on market research, a casing with an inner diameter of 39 mm has been chosen for this application.

- As per the literature [6], the ratio between the flight diameter and the screw shaft is defined as: d = (0,2 - 0,) D = 7 – 15.2 (mm)

Choosing the screw shaft d = 15 (mm)

5.2.2 Determining the power on the screw conveyor

For a vertical screw conveyor, the power on the screw shaft is determined by the formula:

• H = 0,1 (m): Working height of the screw

Substituting into the formula 5.5, we have:

5.2.3 Determining the torque on the screw conveyor

The torque acting on the screw conveyor Tv (N.mm) is determined by the formula:

5.2.4 Determining the axial force on the screw conveyor

The axial force on the screw conveyor:

• R: The distance from the point of friction force application of the material on the screw flight to the screw shaft (mm)

• α: The góc helix angle of the screw flight (degrees), calculated by:

S: The pitch of screw S = D = 35 (mm)

• 𝜸: The friction angle of the material being conveyed with the screw flight (degrees) tg(𝜸) = f f: (friction coefficient for non-abrasive material)

With non-abrasive material: f = 0,65 so 𝜸 = 33,02ᵒ

Substituting into the formula 5.7, we have:

Determining the volume of the hopper

The volume of the hopper V (m 3 ) is determined by the formula:

Preliminary design of the hopper:

Figure 5.2: Preliminary design of the hopper With:

• h1: the height of the truncated cone section of the hopper (mm)

• H: the height of the cylindrical section of the hopper (mm)

• h1: the height of the enclosing pipe section (mm)

• D: Diameter of the hopper (mm)

• α: The angle of hopper compared to the horizontal

- The natural angle of repose of the material is 45 0 ⇒ 𝜶 = 55 0 [6]

The volume of the hopper V (m 3 ) is determined using the volume formula of a truncated cone as follows:

Substituting into the formula 5.11, we have:

Calculation of mixer-wing

5.4.1 Determining the mixer-wing power

The motor power is determined by the formula:

• m: The weight of the product in the hopper (kg) m = 10 kg

• 𝐫 𝐦𝐚𝐱 : Maximum radius of the mixer-wing (m)

• 𝐅: The area of the hopper wall (cm 2 )

• c: specific resistance of the product adhesion force to the wall (kg/cm 2 ) c = 0,7 [4]

• 𝐖: rotational speed of the wing (rpm)

𝟔𝟎 = 𝝅 (𝒓𝒂𝒅/𝒔) Substituting into the formula 5.12, we have:

5.4.2 Determining the torque on the mixer-wing

The torque applied to the mixing blade Tv (N.mm) is determined by the formula:

To ensure easy installation and prevent the mixing blade from scraping against the hopper wall, it is essential to design the blade with appropriate clearance Literature suggests that the gap between the blade and the hopper wall should be between 0.5 to 1 times the diameter of the hopper.

• The length of the large blade: L 0 (mm)

• The length of the small blade: L = 65 (mm)

Torque is determined by multiplying the applied force by the distance from the rotation axis to the point of application Because both large and small blades rotate at the same speed, it is essential to focus on the blade area and the distance from the rotation axis to the blade's midpoint.

The mixer-wing area is calculated as:

𝑨 = Length x Width With the same width, we have:

Torque is directly related to both the wing area and the distance from the rotation axis to the blade's midpoint Consequently, the torque generated by the large blade is twice that of the small blade, resulting in a torque ratio of 2:1 between the two blades.

Selecting the Actual Motor

Electric Motors: In industry, two types of electric motors are commonly used: Direct

Current (DC) motors and Alternating Current (AC) motors

Alternating Current Motors: AC motors are widely used in industry due to their high working durability and high starting torque

Direct Current Motors (DC motors) provide versatile speed control and enable smooth startup, braking, and reversal Despite their advantages, they tend to be more costly to install and necessitate extra components such as rectifiers.

AC motors, despite lacking the speed adjustment capability found in DC motors, are favored for their commonality, robustness, and cost-effectiveness, which make their limitations more acceptable.

Therefore, an AC motor is chosen

Selecting a motor with inadequate power can result in an inability to handle the load or reach the necessary speed, which may cause overheating and shorten the motor's lifespan, ultimately increasing the risk of failure soon after it starts.

Choosing an Overpowered Motor: This results in wasted power and investment costs for the conveyor system, which may also increase the cost of the conveyor system

Selecting the wrong type of motor can lead to significant installation challenges, hindering electricians in their setup process and complicating the procurement of essential ancillary equipment such as circuit breakers and contactors.

If the motor's power is sufficient but it does not reach the required speed (rpm), the conveyor will not meet the operational time requirements of the customer

Motor power is determined by:

Based on the calculations, a motor with a power rating of N đm ≥ 0,0891 KW = 89,1W

Motor Selection: Based on practical conditions and economic benefits, a single-phase

AC motor with an integral gearbox from Oriental Motor (a Japanese motor brand) is chosen The selected motor model is 51K90GU-CW []

Table 5.1: Basic specifications of the motor

Motor type 51K90GU-CW (with integral gearbox)

Shaft’s design and calculations

Determining the maximum compressive force along the shaft acting on the mixing blade

Maximum compressive force acting on the smaller mixing blade

Length of the smaller blade: A = 65 (mm)

Width of the smaller blade: B = 20 (mm)

The axial load on the shaft is calculated using Pascal's law:

• 𝜸 = 741 Ingredient’s density (chicken, carrot, cabbage, ) (kg/m 3 ) (provided by the company)

• 𝑽: Maximum volume of material impacting the blade (m 3 )

V = blade area height from small to large blade = 20.65.123 = 159 900 (mm 3 ) 9 900.10 -9 (m 3 )

Determining the Maximum Radial Force

Maximum radial force located on the large blade

Length of the larger blade: A = 130 (mm)

Mass of the large blade calculated from SolidWorks: m = 25 (g)

The radial force is calculated using Newton's mechanical theory::

• 𝛚 = 𝛑: Angular velocity of the mixing blade (rad/s)

In conclusion, the axial and radial forces acting on the mixing blade are minimal, indicating that the primary consideration for shaft calculation and design should be the torque factor alone.

The shaft diameter is determined by the torque using the formula:

𝛕 = 205 (MPA): Shear stress of inox 304

• 𝐌 𝐗 : Torque determined by the formula (N.mm)

𝟑𝟎 = 28650(N.mm) Substituting into the formula:

Choosing the shaft diameter and roller width according to [5], we have: d = 20mm, b 0 = 15mm

For shafts with mixing blades in practical experiments, people typically choose:

• D: is the diameter of the shaft with the stirring blade (mm)

• d: is the diameter of the shaft transmitting torque to the shaft with the stirring blade (mm)

Shaft diameter with mixing blades: D = 20 – 32 (mm)

Direct shaft diameter for transmitting torque to the mixing blades D = 25 (mm)

The critical section of the shaft is where it connects to the motor, experiencing a maximum torque of T x (363 N.mm) To enhance durability, we selected a motor with a higher power rating than initially calculated, resulting in an increased torque transmitted to the shaft Consequently, we will utilize the torque based on the motor power, T x = 28650 N.mm.

At the section with maximum torque:

❖ Torsional moment resistance of the shaft:

❖ Maximum shear stress generated in the rotating shaft:

According to information, the maximum permissible shear stress of stainless steel 304

=> The shaft meets the strength condition for torsional moment resistance

5.6.3 Shaft Verification using Ansys Software

Analysis software is essential for gaining a comprehensive understanding of deformation capacity and stress in shafts, allowing for the evaluation of their load-bearing capabilities and potential failure risks Key factors considered in this analysis include various stress responses and deformation characteristics.

Table 5.2: Basic Properties of Stainless Steel 304

Figure 5.4 Forces applied to the Shaft

Description: The maximum total deformation is 0.094 mm at the location of the small impeller and shoulder joint

Total length of the shaft segment L = 500 mm

Therefore, the shaft's deformation limit = 𝟎.𝟎𝟗𝟒

Observation: The maximum total deformation (0.0188%) is significantly less than the shaft's deformation limit (0.2%), indicating that the shaft can withstand the load without failure Equivalent Stress

• Description: The maximum von-Mises equivalent stress is 58.024 MPa and occupies a very small area

• Observation: This deformation is within the allowable limit for the material < 205 MPa, indicating that the shaft can withstand the load without failure

• Description: The maximum normal stress along the shaft is 17.777 MPa, which is <

205 MPa and occupies a very small area, with the shaft mainly subjected to 2.5599 MPa of longitudinal stress

• Observation: This deformation is within the allowable limit for the material, showing that the shaft can withstand the load without failure

• Description: The maximum shear stress is 20.883 MPa and the largest coverage area is 2.0708 MPa

• Observation: This deformation is within the allowable limit for the material < 520

MPa, indicating that the shaft can withstand the load without failure.

Calculation of shaft coupling and roller bearings selection

Couplers, which encompass shaft connections, clutches, and automatic clutches, are standard components in mechanical design To select the appropriate coupler dimensions, we often depend on the calculated torque (Tt), determined using a specific formula.

K = 1,5: The working safety factor, depending on the type of working machine, is given in the table (16.1) [5]

Substituting into the formula 5.24 we have:

=> Choosing the flexible coupler joint

Figure 5.9: Flexible coupler joint Table 5.3: Flexible coupler joint parameters

Checking the flexible coupler joint

Substituting into the formula 5.25 we have:

=> Flexible coupler joints satisfy durability conditions

5.7.2 Calculation and selection of roller bearings

• Axial force on the shaft: F av = 278,4 (N)

The total axial force acting on the screw shaft: F a = 1,885.10+ 278,4 = 297,25 (N)

Based on the above parameters and practical considerations, we preliminarily choose the

KOYO bearing with code 6004Z (according to www.vn.misumi-ec.com)

Figure 5.12: Actual image of the bearing

Axial force on the shaft : F a = 297,25 (N)

+ m = 3: curve exponent for roller bearings

𝑳 = 𝟔𝟎 𝟏𝟎 −𝟔 𝒏 𝑳 𝒉 = 𝟔𝟎 𝟏𝟎 −𝟔 𝟑𝟎 𝟔 𝟏𝟎 𝟑 = 𝟏𝟐, 𝟔 (𝒕𝒓𝒊ệ𝒖 𝒗ò𝒏𝒈) + Q: Dynamic load of the roller bearing

+ Qo: Static load of the roller bearing

Basic dynamic load rating 11.7 kN

Basic static load rating 5.05 kN

Therefore, the ball bearing meets the strength condition.

Determining the amount of ingredient loss

Transporting Vietnamese pork sausage with an auger conveyor can lead to significant adhesion issues due to the mixture's unique characteristics, which include meat, vegetables, spices, and oils This adhesion can prevent portions of the sausage mixture from reaching their intended destination, ultimately resulting in material loss.

Measuring material loss in auger conveyors is essential for manufacturers to uphold product quality and meet output volume standards Understanding the extent of material loss allows for necessary design adjustments, ensuring the conveyor system operates effectively and efficiently.

Through numerous experiments, it has been observed that after each batch mixing, the remaining material fills the round tube under the funnel

The volume of the tube will be determined by the formula for the volume of a cylindrical shell:

The weight of lost material will be calculated using the formula: m = γ.V = 741.𝟎, 𝟎𝟎𝟎𝟏𝟕𝟑 =0,128 (kg) With:

In the food and beverage industry, the wastage rate typically ranges from 1% to 3%

Therefore, for each batch of 10kg mixed, our system may experience wastage ranging from

Calculating the time needed to form one portion of core

The time to create the first portion of sausage filling will be the longest because additional time is needed to fill the cylindrical tube under the hopper

• Weight of meat in the cylindrical tube: m = 0,128 (kg)

The time to fill the cylindrical tube is calculated as follows: t 1 = 𝟎,𝟏𝟐𝟖.𝟔𝟎

The time for the auger conveyor to fill the mold chamber: t 2 = 𝟎,𝟎𝟔.𝟔𝟎

• The weight of one portion of core is 60g

Figure 5.14 Measuring mold The total time to form the first portion of core filling will be: t = t 1 + t 2 = 0,349 + 0,164 = 0,513 (minutes)

The time to create subsequent portions of sausage filling will be: t 2 = 0,164 (minutes)

During operation, there is a crucial 2-second period when the mold cannot fully fill with the material due to the ejection process As a result, each filling requires an additional 2 seconds to complete.

The total time to form the first portion of core filling will be: t = t 1 + t 2 = 0,349 + 0,164 +0,033 = 0,546 (minutes)

The total time to form the first portion of core filling will be: t = t 2 +0,033 = 0,164 +0,033 = 0,197 (minutes)

Therefore, the time for the machine to process one batch of 10kg will be:

The number of spring rolls in one 10kg batch: 𝟏𝟎.𝟏𝟎

Thus, in 32,76 minutes the machine can produce 164 pieces, and 300 pieces for an hour.

Calculations and selection of cylinders

5.10.1 Horizontal mold plate pushing cylinder

Total mass to be pushed: m = 1 (kg)

Calculate the force required to push the mold plate

Figure 5.15 Diagram of Forces Acting on the Mold General expression of Newton's second law for a sliding object with friction

• F: force exerted by the cylinder (N)

• a = 0 (object moves with constant velocity): Acceleration of the object

• N: Normal force from the surface

𝑭 𝒎𝒔 = à 𝑵 à = 0,32: The coefficient of friction for POM plastic

Projected onto the Y-axis: N – P = 0 → N = P = m.g → F ms = àN = à.m.g

Projected onto the X-axis: F – 2F ms = ma → F – à.m.g = 0

The formula for calculating the force is F = 2à.m.g = 2.0,32.1.10,8 (N) However, due to machining errors and factors like the smoothness of the guide bar, the actual pulling force required will be significantly higher than the calculated value.

Figure 5.16 Measure pulling force The scale show 4.835 (kg) Let's choose the necessary pulling force F = 6 (kg) = 60 (N)

Determine the parameters of the cylinder

The diameter of the cylinder D (mm) is determined by the following formula:

• F: : force exerted by the cylinder (N)

• P: incoming compressed air pressure (kg/cm 2 )

Substituting into the above formula, we have:

Based on the calculated data above, we choose a cylinder with a stroke length ≥ 100 mm, D

= 40 mm Considering practical conditions and economic benefits due to simplicity, we select cylinder PVN with model number SC40X100-S

Table 5.5: Square head cylinder’s parmameters

To optimize performance, it is crucial to choose a cylinder that provides the necessary stroke length and pushing speed while ensuring minimal frictional resistance This selection guarantees that the component can fall freely and decisively without becoming stuck in the mold, aligning with the specific operational conditions.

We choose the SD20x90 cylinder The pneumatic cylinder SD20x90 is a reliable choice for systems requiring linear motion, ensuring high performance and durability during use

Table 5.6: Compact air cylinder’s parmameters

MANUFACTURING AND EXPERIMENT

Manufacturing the mixing-structure

Figure 6.3: Mixing-structure designed on software Parts in the structure include:

Processing steps: Laser cutting - bending - welding - grinding

Materials: 1mm thickness SAE 304 sheet metal, ∅42mm diameter SAE 304 pipe

Figure 6.4: Hopper appearance Figure 6.5: The pipe welded below the hopper

Figure 6.6: Mixer-shaft designed on software

Processing steps: Laser cutting - bending - grinding

Materials: 3mm thickness SAE 304 sheet metal

Figure 6.7: Mixer-wing designed on software

Processing steps: Lathe - milling - drilling - tapping

Figure 6.8: The connector shaft designed on software Figure 6.9: The complete connector shaft

78 Figure 6.10: Mixing-structure after machining and assembly

Manufacturing the forced-pushing structure

Processing steps: Lathe - cutting - welding

Materials: 1mm thickness SAE 304 sheet metal, SAE 304 workpiece

Figure 6.11: The auger-filler designed on software Figure 6.12: The auger-filler is assembled into the mixer-shaft

Processing steps: Laser cutting - drilling - welding - grinding

Materials: ∅42mm diameter SAE 304 pipe, 5mm thickness SAE 304 sheet metal

Figure 6.13: The complete hopper-pipe Figure 6.14: Surface that contact with the mold

80 Figure 6.15: Checking dimensions and perpendicularity while machining

Manufacturing the measuring mold

6.3.1 Machining the parts from POM plastic

Processing steps: CNC milling - tapping - sanding

Name Parts designed on software Complete parts No

Table 6.7: Machining the parts of the measuring mold

Actual images of the process of machining parts at the CNC machine room, building

E, HCMC University of Technology and Education:

Figure 6.17: The Top-Plate part is completed Figure 6.18: Workpiece is mounted on the vise

6.3.2 Manufacturing the linear bushing support-block

Processing steps: CNC milling - tapping

Figure 6.20: The support-block designed on software

Figure 6.21: The complete support-block and assembled in the structure

Manufacturing the forced-pushing structure

Processing steps: CNC milling - tapping - sanding

Figure 6.22: Push-head designed on software

Figure 6.23: Push-head after machining and assembly

Processing steps: Laser cutting - bending - drilling - boring - grinding

Materials: 2mm thickness SAE 304 sheet metal

Figure 6.24: Push-bar designed on software

Figure 6.25: Push-bar after machining and assembly

6.4.4 Manufacturing the ∅10mm linear shaft

∅20mm shaft designed on software

Figure 6.27: ∅20mm shaft after machining and assembly

∅10mm linear shaft designed on software

Figure 6.29: ∅10mm linear shaft after machining and assembly in the bushing

Processing steps: Laser cutting - bending

Materials: 1mm thickness SAE 304 sheet metal

Figure 6.30: Base-sensor designed on software

Figure 6.31: Base-sensor is assembled with inductive proximity sensor

Manufacturing bases, frame and parts from sheet metal

Processing steps: Laser cutting - bending - drilling - tapping - grinding

Materials: 3mm thickness SAE 304 sheet metal

Figure 6.32: The complete base-hopper-01

Processing steps: Laser cutting - bending - drilling - tapping - grinding

Materials: 3mm thickness SAE 304 sheet metal

Figure 6.33: Base-hopper-02 designed on software

Figure 6.34: The complete base-hopper-02

Processing steps: Laser cutting - bending - drilling - tapping - grinding

Materials: 3mm thickness SAE 304 sheet metal

Figure 6.35: Base-motor-01 designed on software

Figure 6.36: Base-motor-01 (Top surface)

Figure 6.37: Base-motor-01 (Side surface)

Figure 6.38: Base-motor-01 (Bottom surface)

Processing steps: Laser cutting - bending - drilling - tapping - grinding

Materials: 3mm thickness SAE 304 sheet metal

Figure 6.39: Base-motor-02 designed on software Figure 6.40: The complete base-motor-02

Processing steps: Cutting square 40x40mm pipe - laser cutting - welding - grinding Materials: 3mm thickness SAE 304 sheet metal, 40x40mm SAE 304 square pipe

Figure 6.42: Top surface of the frame

Figure 6.43: Frames are assembled on the line

Figure 6.44: Shaft-cover (Top) Figure 6.45: Shaft-cover (Bottom)

Figure 6.46: Shaft-cover designed on software

Figure 6.47: Shaft-cover is assembled with mixer-shaft

Processing steps: Laser cutting - bending - grinding

Materials: 3mm thickness SAE 304 sheet metal

Figure 6.48: Base-cylinder-02 designed on software

Figure 6.49: Base-cylinder-02 is assembled with front of cylinder

Processing steps: Laser cutting - bending - grinding

Materials: 5mm thickness SAE 304 sheet metal

Figure 6.50: Base-cylinder-01 designed on software

Figure 6.51: Base-cylinder-01 is assembled with rear of cylinder

Controller design

6.6.1.1 Introducing the PLC Mitsubishi FX1N-40MT

Figure 6.52: PLC Mitsubishi FX1N-40MT Figure 6.53: Arranging the PLC in electrical cabinet

The PLC FX1N-40MT-ESS/UL, part of the FX1N series, offers numerous advantages, including an affordable price and a compact design Its flexible expansion capability allows it to accommodate up to 128 I/O through specialized control modules Additionally, the FX1N PLC features an integrated position controller suitable for various applications Its robust data exchange and communication capabilities are essential for applications where hardware, communication features, special functions, and processing speed are crucial.

Technical specifications of PLC Mitsubishi FX1N-40MT [22]:

- Expandable for up to 128 inputs/outputs

- Programming software PLC: GX Works2

- LEDs for indicating input & output status

- Available with relay or transistor outputs

Reason for choosing the PLC MITSUBISHIFX0-20MT

- Mitsubishi PLC is a powerful, easy-to-use with wide applications in the market

- Easy to change without loss

- You can customize timer and counter without having to buy additional items

The team chose a 24V-5A DC power supply, designed to convert electric voltage from 220VAC to 24VDC to supply operating equipment

Technical specifications of power supply 24V-5A [24]:

- Overload protection: >25% rated current capacity

Figure 6.54: Power supply 24V 5A Figure 6.55: Arranging the power supply in cabinet

Aptomat is a crucial industrial electrical device commonly utilized in both industrial and civil construction projects Primarily designed for low voltage electrical networks, Aptomat serves the essential function of connecting and disconnecting electrical circuits, effectively preventing overloads and short circuit incidents.

96 protecting the safety of humans and other devices in the electrical network In addition, some types also have more advanced functions such as anti-electric leakage or anti-shock

To prevent short-circuit fires, we need to calculate the appropriate amperage of the machine to choose the appropriate type of Aptomat with function and price:

The power supply has a capacity of 120W and uses 1 phase 220V

Applying the formula: P = U I TT cosφ

=> Choose a circuit breaker with rated current > 1.4A

Therefore, we choose the Aptomat Chint NXB-63 2P C10

Technical specifications of Aptomat Chint NXB-63 2P C10 [15]:

- Standard IEC/EN 60898-1, certification CE

- Rated impulse withstand voltage Uimp (kV): 4kV

- Circuit breaker capability Icu=Ics: 6000A

- Compact design, space saving, high efficiency

- High quality PC plastic material, fire resistant

- Overload protection, short circuit and circuit isolation

- Easy installation on 35mm rails

- Easy to operate, maintain and replace accessories

- Friendly and safe for users

6.6.1.4 Photoelectric sensor OMRON E3Z-LL61 2M OMS

To enable the machine to detect the presence of rice paper on the conveyor, we utilize the OMRON E3Z-LL61 2M OMS photoelectric sensor with a built-in amplifier as the input signal receiver for the PLC This setup allows the PLC to activate the cylinder process, which pushes the mold cavity outward, facilitating the filling to drop onto the rice paper in preparation for the subsequent rolling steps.

Figure 6.58: Arranging the photoelectric sensor onto the base-sensor-02

Technical specifications of OMRON E3Z-LL61 2M OMS [25]:

- Control output: NPN Open collector

6.6.1.5 Inductive proximity sensor LJ18A3-8-Z/BX NPN NO

The LJ18A3-8-Z/BX inductive proximity sensor is a key component in the automation control industry, enabling contactless detection, control, and switching This sensor activates a control signal when it approaches a target object, effectively detecting metal objects with precision.

98 distance of 8mm, without touching objects, suitable for projects of automatic switches, iron line detectors

The sensor in the automatic spring roll making machine is integral to the forced-pushing structure, detecting the up or down movement of the push cylinder It transmits this movement signal to the PLC, which then activates the solenoid valve to control the mold cavity's movement, ensuring it operates smoothly without colliding with the push-head.

Figure 6.59: Inductive proximity sensor LJ18A3-8-Z/BX NPN NO Figure 6.60: Arranging the inductive proximity sensor onto the base-sensor-01

Technical specifications of the inductive proximity sensor LJ18A3-8-Z/BX [20]:

- Operating voltage - DC type: DC12-24V (6-36V)

- Good anti-vibration, long life, fast response speed

- Brown wire: VCC, positive source 6-36VDC

- Blue wire: GND, negative source 0V

- Black wire: signal output NPN

6.6.1.6 The magnetic switch sensor Airtac CS1-U

The Airtac CS1-U magnetic switch sensor is designed to detect the stroke of a cylinder by signaling when it reaches its highest and lowest points Upon contact with the piston, the sensor closes the circuit, transmitting an electrical signal to the control cabinet This enables adjustments to the operating structure, catering to various applications such as food processing and machine assembly.

Figure 6.61: The magnetic switch sensor

Figure 6.62: Arranging a magnetic switch sensor on the cylinder

Technical specifications of Airtac CS1-U [21]:

- Switch logic: STSP Normally opened type

- High sensitivity and stable performance

A pneumatic solenoid valve, also known as a reversing valve, regulates the flow of compressed air within a system It effectively directs compressed air into multiple pathways by utilizing an electric current to generate a magnetic field, which in turn opens and closes the valve.

The Airtac 4V220-08 pneumatic solenoid valve is a versatile 5/2 solenoid valve featuring dual electric coils that can function with both DC and AC voltage sources This series includes reversible pneumatic solenoid valves with five ports, allowing for two specific opening and closing directions, making it an efficient choice for various applications.

Figure 6.63: Pneumatic solenoid valve AIRTAC 4V220-08 Figure 6.64: Arranging pneumatic solenoid valve

- Port size in/out: 1/4”- thread 13

- Temperature: 220 VAC, 24 VDC, 110 VAC, 12 VDC

6.6.1.8 Other components in the controller

STT Devices Pictures Function Quantity

Emergency power off in case of problem 1

“Ready” button, supplying power to start the sensor and run the machine

“Test” button, checking and testing the machine when starting up

Connecting the air hose to the cylinder, adjust the amount of compressed air in and out of the cylinder, adjust the speed of the pneumatic cylinder

Adding more contacts to the magnatic switch sensor to connect PLC 2

Controlling the speed of the motor 1

Fixing the power cord, making it easy to remove and install the wire

Arrange and protect electrical equipment 1

Table 6.8: Summary table of other components in the controller

6.6.2 Circuit design and PLC programming

6.6.2.1 Flow chart of machine control algorithm

Figure 6.65: Flow chart of machine control algorithm

Figure 6.66: Power Suply Figure 6.67: Motor circuit

Figure 6.71: Arrange equipment in electrical cabinets Figure 6.72: Button layout

6.6.2.3 Programming PLC Mitsubishi FX1N-40MT

Table 6.9: Summary table of PLC's Input and Output hardware

6.6.2.4 Operating principle of the machine's electrical circuit

To initiate the circuit, first close the Aptomat MCB and then press the “Power” button To supply power to the PLC, press the “Ready” button Before fully automating the machine, ensure proper sensor functionality by pressing the "Test" button, prompting the PLC to operate The PLC powers the pneumatic valve of cylinder 1, allowing the piston to extend the mold cavity Once the piston completes its stroke and activates the magnetic sensor, it sends an input signal to the PLC after time t1 This signal triggers the PLC to power the pneumatic valve of cylinder 2, causing the piston to push down When the piston reaches the bottom and activates the proximity sensor, it sends another input signal to the PLC, which then generates an output signal to power the pneumatic valve of cylinder 2, completing the cycle.

At the end of the stroke, the piston activates the upper proximity sensor, which after a set time (t2), sends a signal to the PLC This signal prompts the pneumatic valve of cylinder 1 to return to its original position within the measuring mold Following another time interval (t3), the program resets, preparing for the next cycle When rice paper is placed on the conveyor belt and reaches the OMRON optical sensor, the sensor sends an input signal to the PLC, triggering the entire sequence of operations.

Turn the knob on the speed adjuster to adjust the rotation speed of the mixer-shaft

When the “E-Stop” button is pressed, the PLC is disconnected and stops all machine operations

Figure 6.74: Pneumatic cylinder state diagram

Manufacturing and experiment

6.7.1 Assembly and complete of the machine

Proper disassembly and assembly of machine parts are crucial for effective cleaning, maintenance, and repairs To streamline this process and prevent confusion, it's essential to follow a clear sequence that prioritizes safety and convenience Adhering to the assembly instructions ensures that all mechanisms function correctly, ultimately saving valuable time and enhancing the machine's performance.

The assembly sequence of the machine parts is as follows:

Figure 6.75: Releasing structure when not assembled

Step 1: Installing the mixer-shaft

Figure 6.76: Mixer-shaft installation sequence

Figure 6.77: Install the circlip to fix the mixer-shaft Figure 6.78: Completed shaft installation

Step 3: Installing the measuring mold

Figure 6.82: Putting the measuring mold into position

Figure 6.83: Installing the screws in 4 cornner diagonally Figure 6.80: Installing the screws Figure 6.81: Finished installing the engine

The mold housing must be installed accurately to prevent the hopper from scraping the mixer-wing

Figure 6.86: Insert the hopper and hopper-pipe into the mixer-shaft

Figure 6.87: Install the quick clamping to connect the hopper and hopper- pipe

Figure 6.84: Screw the cylinder into the cavity of the mold

Figure 6.85: The measuring mold installation completed

Figure 6.88: Fix the hopper-pipe into the measuring mold with screws Figure 6.89: Hopper installation completed

Figure 6.90: The filling releasing structure is completely installed on the automatic spring rolls making machine

6.7.2 Experimentation and addressing external issues of the machine

Purpose: To check the external condition of the machine, examine vibrations, and noise during operation to ensure longevity, energy savings, reduced component wear, and compliance with food safety standards

To organize experiments effectively, operate the machine without any load, adjust the rotation speed of the mixing shaft, and initiate the process by pressing the "Test" button to run both cylinders while monitoring the sensors The evaluation involves a visual assessment of the machine's external condition.

To execute the method and collect data, operate the machine without any load, set the mixing shaft's rotation speed between 50-70 RPM, and use the "Test" button along with the pneumatic valve's control buttons to manage the cylinders.

The results are as follows:

No Result Detects Solution Example

The parts are machined to the required dimensions, surfaces are clean, assembly is complete, and parts can be easily disassembled for cleaning

When running without load, the hopper and mixing blades scrape each other causing noise and vibration

Adjust the frame and hopper position so the mixing shaft and hopper are concentric to minimize collision

6.7.3 Experimentation and addressing operational issues of the machine

This study aims to evaluate how various factors, such as mold material, mixing blade rotation force, forced push cylinder speed, material compression, and screw fill rate, impact the machine's efficiency in dosing and shaping spring roll filling The objective is to ensure precise placement of the filling onto rice paper while minimizing mass loss during the process.

Equipment and materials for the experiment:

Materials: 10kg Spring Roll Filling Consisting of Chicken and Various Ingredients Mixed According to the Restaurant Owner's Recipe:

• Wood Ear Mushrooms: 500g (soaked in water and finely chopped)

To ensure long-term preservation and maintain stickiness, the spring roll filling is mixed and refrigerated It is portioned for use over several days, with each batch utilizing 5kg of filling in the hopper The filling is then extruded into the mold cavity via a screw conveyor, while rice paper wrappers are fed sequentially onto the conveyor belt for the filling process.

Figure 6.91: Loading the Filling into the Mixing Hopper

The effectiveness of the machine's filling dosing is assessed by measuring the output filling dimensions with a ruler, weighing the output using a scale, and evaluating its wrapping capability in subsequent stages.

The experiment involves placing spring roll wrappers on a conveyor belt to receive filling until the mold cavity is empty Each trial is conducted at sequential rotation speeds of 10 to 100 RPM, utilizing a motor speed controller, with a new wrapper fed every 12 seconds.

The filling had some adhesion, but the mold cavity was not fully filled The output filling weight was only about 70% of the required weight

The filling dropped correctly onto the wrapper, meeting the size and weight requirements, with good ingredient adhesion

The filling structure was too compressed, exceeding the required weight (>110%)

Despite maintaining a speed of 40 RPM, the filling began to leak water, resulting in it adhering to the pusher instead of properly dropping onto the wrapper This issue caused clogging and improper filling.

Table 6.10: Experimental Results of Machine Operation

In the experiment, the team observed that at 30 RPM, the fillings achieved a uniform size and appearance, with weights ranging from 90-110% (52g-64g) of the target weight of 60g ±5g across 10 trials, confirming consistency with the initial data.

At 30 RPM, with a 12-second interval between each releasing cycle, some issues arose that need fixing:

Cylinder’s force Cylinder’s speed Airflow rate (throttle valve discharge level)

Cases Problems Reason Adjustment Result

The cylinder speed pushes the mold cavity out slowly

The mold cavity pushed out slowly compared to the rice paper's moving speed, causing deviation in the falling position

Close the throttle valve at low air flow levels (